AUTHOR=Zhu Youjuan , Kong Yichao , Hong Yu , Zhang Ling , Li Simin , Hou Shurong , Chen Xiabin , Xie Tian , Hu Yang , Wang Xiachang 

TITLE=Huoshanmycins A‒C, New Polyketide Dimers Produced by Endophytic Streptomyces sp. HS-3-L-1 From Dendrobium huoshanense

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.807508

DOI=10.3389/fchem.2021.807508

ISSN=2296-2646

ABSTRACT=<p>Three new polyketide dimers named huoshanmycins A‒C (<bold>1</bold>–<bold>3</bold>) were isolated from a plant endophytic <italic>Streptomyces</italic> sp. HS-3-L-1 in the leaf of <italic>Dendrobium huoshanense</italic>, which was collected from the Cultivation base in Jiuxianzun Huoshanshihu Co., Ltd. The dimeric structures of huoshanmycins were composed of unusual polyketides SEK43, SEK15, or UWM4, with a unique methylene linkage. Their structures were elucidated through comprehensive 1D-/2D-NMR and HRESIMS spectroscopic data analysis. The cytotoxicity against MV4-11 human leukemia cell by the Cell Counting Kit-8 (CCK8) method was evaluated using isolated compounds with triptolide as positive control (IC<sub>50</sub>: 1.1 ± 0.4 μM). Huoshanmycins A and B (<bold>1</bold>, <bold>2</bold>) displayed moderate cytotoxicity with IC<sub>50</sub> values of 32.9 ± 7.2 and 33.2 ± 6.1 μM, respectively.</p>